The central leadership has its constitutional rights and responsibilities regarding the political structure of Hong Kong, the city's chief secretary told a group of students on Tuesday who have initiated illegal protests that have blocked streets for three weeks.

Voters in Hong Kong could select their leader, for the first time by universal suffrage in 2017, according to a resolution adopted by the National People's Congress Standing Committee on Aug 31.

The "ultimate aim" of universal suffrage is enshrined in the Basic Law, in which nominees for the city's next leader will be produced by a "broadly representative nominating committee in accordance with democratic procedures". Rules were set out for this committee in the resolution adopted in August.